In commercial cannabis cultivation, the THC content is used as a measurement fordefining the medical potential.The THC content can vary widely, an accurate assessment of the medical potential is therefore of difficult.(Potter 2013, Vanhove 2011)In addition to the genetically potential of a plant the influencing factors on the THC content can be divided into two categories: Cultivation phase / Post-harvest phase.Cultivation phase consists of following factors:cultivation system , temperature, nutrient availability, light intensity,ultraviolet light, light quality, light duration, varietey, humidity and stress(Hammerwick 2012, Small 2015, Khan 2004, McLaren 2008).Post-harvest phase consist of following factors:harvesting time, analyzed plant material ( root, flower ,leaf) processing ( oil>hash>flower)storage period and condition (Niesink 2015, McLaren 2008, Khan 2004).
The cannabis boom led to cultivation techniques, with increasing use of pesticides, fertilizers and plant hormones.
Many patients already focus on Cannabis from organic cultivation, beeing afraid of toxic residues used in conventional farming.In various studies, residues of fungi and bacteria were detected in cannabis products.The extent to which biotic and chemical residues are associated with a specific cultivation system and storage type has not been investigated yet. Hydroponic systems are often considered to be unnatural and are not much accepted by patients.Nevertheless, hydrophonic cultivation under controlled conditions can help to grow healthy plants with homogenous ingredient profile and should be further investigated.